| Image processing device and image processing method -> Monitor Keywords |
|
|
  Image processing device and image processing methodUSPTO Application #: 20060109308Title: Image processing device and image processing method Abstract: An image processing device includes a binarization unit for converting a pixel value of image data into binary data, the pixel value showing a gradation value of a pixel, the image data including a plurality of pixels, the pixels being laid out as a matrix, the binary data showing a dot radius of a unit dot, the unit dot being laid out with lower resolution than the maximum print resolution at least in a direction of print media feeding direction; an expansion dot generation unit for generating print control data on the basis of the binary data obtained by the binarization unit, the print control data including data showing dot radii of a standard dot and an expansion dot, the standard dot being formed at a location, the location being determined on the basis of the unit dot, the expansion dot being formed at a different location to the standard dot; and an output unit for outputting to a image forming device the print control data generated by the expansion dot generation unit, the image forming device having a plurality of nozzles, the nozzle ejecting an ink dot; wherein a density of an image including the standard dot and the expansion dot is approximately equal to a density of an image including the unit dot. (end of abstract) Agent: Harness, Dickey & Pierce, P.L.C - Bloomfield Hills, MI, US Inventor: Toru Miyamoto USPTO Applicaton #: 20060109308 - Class: 347043000 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20060109308. Brief Patent Description - Full Patent Description - Patent Application Claims
[0001] The entire disclosures of Japanese Patent Application No. 2004-339912, filed Nov. 25, 2004, Japanese Patent Application No. 2005-012417, filed Jan. 20, 2005, and Japanese Patent Application No. 2005-244667, filed Aug. 25, 2005 are expressly incorporated by reference herein. BACKGROUND [0002] 1. Technical Field [0003] The present invention relates to an image processing device. Specifically, the present invention relates to an ink jet printer for outputting color ink in particulate form (ink dots) onto a print media to thereby form desired characters and images. [0004] 2. Related Art [0005] In line with widespread consumer use of personal computers, digital cameras, and so on, ink jet printers are also now widely used by consumers, as well as in offices. The popularity of such printers is due to their ability to provide high quality color printing at a low cost. [0006] Generally, ink jet printers have a carriage in which ink cartridges with integral printing heads are provided. In operation, the carriage of the printer is caused to scan in a direction orthogonal to that in which a sheet for printing is fed through the printer (chassis), and ink is ejected in particulate form from the printing heads onto a print media to thereby form thereon desired characters and images. Ink jet printers are capable of forming color images as well as monochrome images by use of a carriage having color ink cartridges (for example, black (K), yellow (Y), magenta (M), and cyan (C)), the cartridges being provided with an integral printing head. To obtain higher quality color images, recently some ink jet printers have been developed having six, seven, or eight color ink cartridges (for example, light-cyan and light-magenta as well as YMCK). [0007] An ink jet printer that carries out printing by scanning of its cartridge carriage in a direction orthogonal to a print media feeding direction is called as "multi-pass printer". In using such a printer, to obtain an image that covers the entire surface of the print media, it is necessary for the carriage of the printer to scan orthogonal to the media tens of hundreds of times. Consequently, such printers suffer from a disadvantage in that they take a long time to print an image as compared to, for example, laser printers using electrophotography. [0008] To attain high speed printing, there has been developed an ink jet printer having a long printing head and no carriage. This type of ink jet printer is referred to as a "line head printer". In using a line head printer, there is no necessity to move a printing head in a direction orthogonal to that of feeding of print media. A line head printer carries out so-called "single-pass printing"; and is able to produce prints at a rate that is as fast as that of a laser printer. [0009] The printing head of a single-pass printer is provided with micro nozzles having a diameter of 10-70 micrometers. The nozzles are provided in the printing head at regular intervals; and their layout may be such as is capable of printing a plurality of lines. In a case that an output direction of a nozzle of such a printing head deviates from its ideal direction because of a fabrication error, or in a case that a position of the nozzle deviates from its ideal position because of a fabrication error, an ink dot formed on a paper by the nozzle will also deviate from its ideal position This phenomenon is referred to as "splash bending", and causes print errors. [0010] Specifically, splash bending causes a deterioration in print quality. Specifically, intervals between two ink dots are made non-uniform dependent on a splash bending. Thus, at a part of a printed image in which two ink dots are printed at an interval that is longer than the ideal interval, a light band (or a white band) is likely to appear; and at a part of printed image in which two ink dots are printed at an interval that is shorter than the ideal interval, a dark band is likely to appear. This phenomenon is referred to as "banding". [0011] It is possible in a multi-pass printer to alleviate or prevent such banding by repeatedly moving the printing head. However, in a single pass printer it is not possible to move the printing head in this manner and therefore banding may become a serious problem. [0012] To prevent banding, two approaches are available. One approach is to improve hardware such as a printing head or a carriage. The other approach is to improve software for processing image data. For example, JP-A-2003-094620 discloses a software approach to prevent banding. JP-A-2003-094620 discloses an image processing method by which ink dots are laid out in a staggered arrangement. In a case that the resolution of a printed image is 720 dpi (dot per inch), the ink dots are laid out on lattice points whose interval is 1/720inch in accordance with the normal image processing. However, the interval between two ink dots is 1/720/{square root over (2)} in accordance with JP-A-2003-094620. In other words, by employing the image processing method disclosed in JP-A-2003-094620, the effective print resolution becomes 1/{square root over (2)} of the maximum resolution. [0013] According to JP-A-2003-094620, binarization can be reduced to 1/{square root over (2)} of that according to a usual image processing method. However, JP-A-2003-094620 is subject to a problem in that the print resolution also becomes 1/{square root over (2)} of the maximum resolution attained by a usual image processing method. While an image processing device is required to be capable of both high speed and high quality print output, JP-A-2003-094620 is unable to provide high quality print output because its print resolution is lower than that attained by a usual image processing method. SUMMARY [0014] An advantage of some aspects of the invention is to provide an image processing device that is capable of reducing binarization while obtaining high quality printing, including prevention of banding. [0015] According to an aspect of the invention, an image processing device comprises: a binarization unit for converting a pixel value of image data into binary data, the pixel value showing a gradation value of a pixel, the image data including a plurality of pixels, the pixels being laid out as a matrix, the binary data showing a dot radius of a unit dot, the unit dot being laid out with lower resolution than the maximum print resolution at least in a direction of print media feeding direction; an expansion dot generation unit for generating print control data on the basis of the binary data obtained by the binarization unit, the print control data including data showing dot radii of a standard dot and an expansion dot, the standard dot being formed at a location, the location being determined on the basis of the unit dot, the expansion dot being formed at a different location to the standard dot; and an output unit for outputting to a image forming device the print control data generated by the expansion dot generation unit, the image forming device having a plurality of nozzles, the nozzle ejecting an ink dot; wherein a density of an image including the standard dot and the expansion dot is approximately equal to a density of an image including the unit dot. [0016] According to the image processing device, the binarization frequency is decreased to a predetermined number corresponding to a predetermined resolution that is less than the maximum print resolution. Furthermore, the standard dots and the expansion dots provides high quality print in view of granularity. In addition, the expansion dots are formed so as to have an offset, thereby provides high quality print in view of banding. The standard dots and the expansion dots may be formed by different nozzles. The output characteristic of the nozzles for the standard dot and nozzles for the expansion dot may be different from each other. The nozzles for the expansion dot may be manufactured with low accuracy. The low accuracy nozzle can be manufactured at a low cost. [0017] It is preferable that the expansion dot is formed at the nearest location to the corresponding standard dot. [0018] It is preferable that the expansion dot is formed by one of a plurality of nozzles that is located next to a nozzle ejecting the standard dot. In addition, the expansion dot is formed on a line that is next to a line on which the standard dot is formed. [0019] It is preferable that the dot radius of the standard dot is greater than or equal to that of the corresponding expansion dot. [0020] It is preferable that each of the dot radius of the standard dot and the expansion dot is an integer multiple of the minimum dot radius. [0021] It is preferable that the expansion dot generation unit changes the layout of the standard dot and the expansion dot at a predetermined interval. In addition, it is preferable that the layout is changed in a direction of print media feeding direction or in a direction orthogonal to the print media feeding direction. [0022] It is preferable that the image processing device further comprises: a deviation memory for storing deviations of densities of dots from ideal densities. In addition, it is preferable that the dots are formed by a plurality of nozzles. Furthermore, it is preferable that the expansion dot generation unit determines the dot radius of the expansion dot on the basis of the deviation of a nozzle ejecting the standard dot next to the expansion dot. Continue reading... Full patent description for Image processing device and image processing method Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Image processing device and image processing method patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Image processing device and image processing method or other areas of interest. ### Previous Patent Application: Wide-format print engine with a pagewidth ink reservoir assembly Next Patent Application: Doubly-anchored thermal actuator having varying flexural rigidity Industry Class: Incremental printing of symbolic information ### FreshPatents.com Support Thank you for viewing the Image processing device and image processing method patent info. IP-related news and info Results in 0.72196 seconds Other interesting Feshpatents.com categories: Medical: Surgery , Surgery(2) , Surgery(3) , Drug , Drug(2) , Prosthesis , Dentistry |
||
